The invention relates to an installation switch for building installation, and particularly a switch for switching the mains voltage as well as a switch for switching a low voltage.
The switches commonly used for building installation are mechanical switches comprising a switching lever arranged to connect various contacts. Further, touch-operated switches exist wherein a sensor face is merely touched to initiate a switching process. Touch switches of this type have an installation housing sized to fit into the installation box and containing the electronics. The installation box has a touch panel arranged externally thereof. The outer appearance of such touch switches is similar to that of usual mechanical installation switches.
A touch switch element known from WO 92/04724 is arranged between two glass plates. By application of pressure on the glass plates, these are locally pressed together, thus closing an electric contact at the pressure site. These glass plates form a transparent plate structure. The electric traces arranged therebetween are likewise made from a transparent material which is hardly visible by the unaided eye.
It is an object of the invention to provide an installation switch for building installation which, as compared to conventional installation switches, offers a wider variability regarding the switching functions, the constructional design and the outer appearance.
In the installation switch of the invention, the touch panel is provided as a transparent plate comprising at least one pressure-actuated switch organ. This plate is a component of a largely nondistinct optical appearance and is not easily discernible as a switch or operating element. The plate can have different touch fields arranged thereon which correspond to different switching functions. The touch elements of touch switches must have a certain size and certain mutual distances to allow their selective operation by the touch of a finger. As a result, touch switches for a plurality of switching functions will form relatively large panels which give a clumsy visual impression. In the installation switch of the invention, any desired number of switch areas or touch fields can be provided while the overall touch panel will still not look bulky or large-surfaced. This is because a transparent switching plate is not optically perceived as a switch means and appears as a mere ornament.
Preferably, the touch panel is arranged on the base portion in such a manner that an open free space is provided under the plate. In the present context, an open free space is meant to a hollow space which is open laterally or also in the downward direction. At least a portion of the glass plate which is provided with touch elements is not supported at its back. Support can be provided either at one end of the plate, thus having the plate freely project in a cantilevered manner, or on opposite edges.
In the installation switch of the invention, the plate forming the carrier for the switch elements has the appearance of a light-weighted and flat component whose electric function is visually hidden from the observer and which will be perceived as an optical ornament. Nonetheless, the plate supports at least one switch element and preferably a plurality of switch elements. This makes it possible to enlarge the functionally effective touch area far beyond the outer surface area of the installation box without causing the switch panel to take on a massive and large-surfaced impression. Of course, the switch elements can be marked on the plate by contoured or colored fields so that the user will know which touch field to press for initiating a respective function.
Preferably, the touch panel is oriented at an inclination in the manner of a lectern. Since the switches are normally arranged below eye level, the user""s glace will in this embodiment fall almost perpendicularly onto the plate. Further, pressing the switch elements is facilitated.
The base portion having the touch panel attached thereon is suitably provided with contacts and holding elements, arranged to engage electric contacts of the installation housing and respectively mechanical holding supports of the support plate. In this manner, the base portion can be mounted to the installation housing and the support plate, respectively. In many cases, a simple plug connection will be sufficient for reliable attachment of the base portion to the installation housing. However, also an additional screw-type connection can be provided for secure attachment.
The base portion preferably includes an electronic selection circuit for generating, from the touch signals, transmission signals to a circuit included in the installation housing. This feature pertains to the case where the touch panel comprises a plurality of switch elements. The touch signal generated upon actuation of a switch element is a low voltage signal which is first processed in the selection circuit and then is supplied to the circuit included in the installation housing. This offers the possibility to connect the base portion to the installation housing via a two-pole plug adapted to transmit signals from more than one switch element, e.g. by encoding.
The installation switch can be provided as a mains switch for switching the voltage of the supply network. In this case, the installation housing is provided with a power switch which is preferably arranged as an electronic switch. This switch can also have an additional dimming function. However, it is also possible to provide the installation switch as a low voltage switch for in-house information distribution network technology. In this case, the installation housing includes a bus coupling device with microprocessor, for exchanging telegrams with other bus coupling devices or a central unit via a bus installed in the building. These telegrams contain information on the switch state of the switch elements of the respective installation switch.
Embodiments of the invention will be explained in greater detail hereunder with reference to the drawings.